Bulk-friction modeling of afterslip and the modified Omori law
Leif Wennerberg, Robert V. Sharp
1997, Tectonophysics (277) 109-136
Afterslip data from the Superstition Hills fault in southern California, a creep event on the same fault, the modified Omori law, and cumulative moments from aftershocks of the 1957 Aleutian Islands earthquake all indicate that the original formulation by Dieterich (1981) [Constitutive properties of faults with simulated gouge. AGU, Geophys....
Kinetics of DCE and VC mineralization under methanogenic and Fe(III)- reducing conditions
P. M. Bradley, F. H. Chapelle
1997, Environmental Science & Technology (31) 2692-2696
The kinetics of anaerobic mineralization of DCE and VC under methanogenic and Fe(III)-reducing conditions as a function of dissolved contaminant concentration were evaluated. Microorganisms indigenous to creek bed sedi ments, where groundwater contaminated with chlorinated ethenes continuously discharges, demonstrated significant mineralization of DCE and VC under methanogenic...
Growth of a tectonic ridge during the Landers earthquake
R. W. Fleming, A. M. Johnson
1997, Geology (25) 323-326
The formation of tectonic ridges by localized vertical uplift along strike-slip faults has long been suspected, but the actual growth of a tectonic ridge during an earthquake has never been documented. During the 1992 Landers, California, earthquake sequence, an awl-shaped, dome-like topographic ridge...
Recovery strategies for the California clapper rail (Rallus longirostris obsoletus) in the heavily-urbanized San Francisco estuarine ecosystem
Theodore C. Foin, E. Jacqueline Garcia, Robert E. Gill Jr., Steven D. Culberson, Joshua N. Collins
1997, Landscape and Urban Planning (38) 229-243
The California clapper rail (Rallus longirostris obsoletus), a Federal- and State-listed endangered marsh bird, has a geographic range restricted to one of the most heavily-urbanized estuaries in the world. The rail population has long been in a state of decline, although the exact contribution of each of the many contributing...
Mapping of the Moon by Clementine
A. S. McEwen, M.S. Robinson
1997, Advances in Space Research (19) 1523-1533
The "faster, cheaper, better" Clementine spacecraft mission mapped the Moon from February 19 to May 3, 1994. Global coverage was acquired in 11 spectral bandpasses from 415 to 2792 nm and at resolutions of 80-330 m/pixel; a thermal-infrared camera sampled ???20% of the surface; a high-resolution camera sampled selected areas...
The urban atmosphere as a non-point source for the transport of MTBE and other volatile organic compounds (VOCS) to shallow groundwater
J. F. Pankow, N.R. Thomson, Richard L. Johnson, A. L. Baehr, J.S. Zogorski
1997, Environmental Science & Technology (31) 2821-2828
Infiltration and dispersion (including molecular diffusion) can transport volatile organic compounds (VOCs) from urban air into shallow groundwater. The gasoline additive methyl-tert-butyl ether (MTBE) is of special interest because of its (1) current levels in some urban air, (2) strong partitioning from air into water, (3) resistance to degradation, (4)...
Food and prey selection of recently released American shad (Alosa sapidissima) larvae
J. H. Johnson, D. S. Dropkin
1997, Journal of Freshwater Ecology (12) 355-358
We examined the diet composition and prey selection of 1,875 recently released American shad (Alosa sapidissima) larvae (approximately 18-d old). Larvae were collected in the Juniata River, Pennsylvania, during June in 1991 and 1992. Chironomid pupae were selected by shad larvae and were the major component in...
Applications of the 190Pt-186Os isotope system to geochemistry and cosmochemistry
R.J. Walker, J. W. Morgan, E.S. Beary, M.I. Smoliar, G.K. Czamanske, M.F. Horan
1997, Geochimica et Cosmochimica Acta (61) 4799-4807
Platinum is fractionated from osmium primarily as a consequence of processes involving sulfide and metal crystallization. Consequently, the 190Pt186Os isotope system (190Pt → 186Os + α) shows promise for dating some types of magmatic sulfide ores and evolved iron meteorites. The first 190Pt 186Os isochrons are presented here for ores from the ca. 251...
Comment on "The 1946 Hispaniola earthquake and the tectonics of the North America-Caribbean plate boundary zone, northeastern Hispaniola"
J.F. Dolan, D.J. Wald
1997, Journal of Geophysical Research B: Solid Earth (102) 785-792
No abstract available....
Comparison of phytoplankton succession in two lakes of different mixing regimes
M.D. Agbeti, J.C. Kingston, J. P. Smol, C. Watters
1997, Archiv fur Hydrobiologie (140) 37-69
The influence of frequent water-column mixing on phytoplankton succession and species composition was studied by comparing plankton dynamics in two lakes (Lake Opinicon and Upper Rock Lake) which have similar water chemistry, but differ widely in their basin morphometries: Opinicon is shallow and frequently-mixed during the ice-free season, whereas nearby...
The use of multifrequency and polarimetric SIR-C/X-SAR data in geologic studies of Bir Safsaf, Egypt
G. G. Schaber, J.F. McCauley, C. S. Breed
1997, Remote Sensing of Environment (59) 337-363
Bir Safsaf, within the hyperarid 'core' of the Sahara in the Western Desert of Egypt, was recognized following the SIR-A and SIR-B missions in the 1980s as one of the key localities in northeast Africa, where penetration of dry sand by radar signals delineates previously unknown, sand-buried paleodrainage valleys ('radar-rivers')...
Timing of detachment faulting in the Bullfrog Hills and Bare Mountain area, southwest Nevada: Inferences from 40Ar/39Ar, K-Ar, U-Pb, and fission track thermochronology
T.D. Hoisch, M.T. Heizler, R. E. Zartman
1997, Journal of Geophysical Research B: Solid Earth (102) 2815-2833
Crustal extension in the Bullfrog Hills and Bare Mountain area of southwest Nevada is associated with movement along a regional detachment fault. Normal faulting in the upper plate and rapid cooling (denudation) of the lower plate were coeval with Miocene silicic volcanism and with west-northwest transport along the detachment fault....
An X-ray diffraction method for semiquantitative mineralogical analysis of Chilean nitrate ore
J.C. Jackson, G.E. Ericksent
1997, Revista Geologica de Chile (24) 45-54
Computer analysis of X-ray diffraction (XRD) data provides a simple method for determining the semiquantitative mineralogical composition of naturally occurring mixtures of saline minerals. The method herein described was adapted from a computer program for the study of mixtures of naturally occurring clay minerals. The program evaluates the relative intensities...
Distribution of MTBE in ground water in New England by aquifer type and land use
S. J. Grady
1997, ACS Division of Environmental Chemistry, Preprints (37) 392-394
[No abstract available]...
Modeling saltwater upconing in a freshwater aquifer in south-central Kansas
T.-S. Ma, M. Sophocleous, Y.-S. Yu, R. W. Buddemeier
1997, Journal of Hydrology (201) 120-137
The Great Bend Prairie freshwater alluvial aquifer in south-central Kansas overlies a bedrock brine aquifer of Permian age. The continuous extraction of freshwater mainly for irrigation in this area has accelerated the upward movement of the saltwater, resulting in the deterioration of water quality. Predicting saltwater upconing is critical for...
Activated char from Illinois coal for combined SO2/NOx removal
A.A. Lizzio, A.M. Chang, J.L. Haslbeck
1997, ACS Division of Fuel Chemistry, Preprints (42) 867-869
[No abstract available]...
Experimental design for estimating parameters of rate-limited mass transfer: Analysis of stream tracer studies
Brian J. Wagner, Judson W. Harvey
1997, Water Resources Research (33) 1731-1741
Tracer experiments are valuable tools for analyzing the transport characteristics of streams and their interactions with shallow groundwater. The focus of this work is the design of tracer studies in high-gradient stream systems subject to advection, dispersion, groundwater inflow, and exchange between the active channel and zones in surface or...
El Salvador, Chile porphyry copper deposit revisited: Geologic and geochronologic framework
P. Cornejo, R. M. Tosdal, C. Mpodozis, A.J. Tomlinson, O. Rivera, C.M. Fanning
1997, International Geology Review (39) 22-54
The Eocene (42 to 41 Ma) El Salvador porphyry copper deposit in the Indio Muerto district, northern Chile (26° 15′ S Lat.), formerly thought to have formed at the culmination of a 9-m.y. period of episodic magmatism, is shown by new mapping, U-Pb and K-Ar geochronology, and petrologic data...
Resistance formulas in hydraulics-based models for routing debris flows
Cheng-lung Chen, Chi-Hai Ling
1997, Conference Paper, International Conference on Debris-Flow Hazards Mitigation: Mechanics, Prediction, and Assessment, Proceedings
The one-dimensional, cross-section-averaged flow equations formulated for routing debris flows down a narrow valley are identical to those for clear-water flow, except for the differences in the values of the flow parameters, such as the momentum (or energy) correction factor, resistance coefficient, and friction slope. Though these flow parameters for...
Tracing hydrologic pathways at the Panola Mountain Research Watershed, Georgia, USA
N.E. Peters, E.B. Ratcliffe
1997, IAHS-AISH Publication (244) 275-289
An analysis of Cl- concentrations and fluxes at the Panola Mountain Research Watershed indicates that Cl- may be effectively used to differentiate "new" and "old" water flow through the hillslope and their respective contributions to streamwater. Rainfall and throughfall, the "new" water inputs, are marked by low Cl- concentrations (<15...
Organic carbon balance and net ecosystem metabolism in Chesapeake Bay
W. M. Kemp, E.M. Smith, M. Marvin-DiPasquale, W.R. Boynton
1997, Marine Ecology Progress Series (150) 229-248
The major fluxes of organic carbon associated with physical transport and biological metabolism were compiled, analyzed and compared for the mainstem portion of Chesapeake Bay (USA). In addition, 5 independent methods were used to calculate the annual mean net ecosystem metabolism (NEM = production - respiration) for the integrated Bay....
Volcanic resurfacing of Io: Post-repair HST imaging
J.R. Spencer, A. S. McEwen, M.A. McGrath, P. Sartoretti, D.B. Nash, K. S. Noll, D. Gilmore
1997, Icarus (127) 221-237
In March 1994, we used the newly refurbished Hubble Space Telescope (HST) to obtain global imaging of Io at five wavelengths between 0.34 and 1.02 μm, with a spatial resolution of 160 km. The images provided the clearest view of Io...
Geomicrobiology of sulfide mineral oxidation
D. Kirk Nordstrom, G. Southam
1997, Reviews in Mineralogy (35) 381-390
[No abstract available]...
Laboratory biological testing of new acid mine drainage treatment technology provides support for field applications
M. Cole, D. Arnold, R. Ross, B. Watten
1997, Slate Run Tackle Shop Newsletter (1996) 17-18
Formation of ferric iron crusts in Quaternary sediments of Lake Baikal, Russia, and implications for paleoclimate
R.G. Deike, L. Granina, E. Callender, J. J. McGee
1997, Marine Geology (139) 21-46
Phosphate-bearing, ferric iron and siliceous crusts ranging in age from Recent to approximately 65,000 yr B.P. are observed in sediments of Lake Baikal. In younger sediments the crusts are at the base of a spectrum of secondary iron and manganese oxides that accumulate near the sediment/water interface in the zone...
